Electronic device, circuit, and method



May 1945. T. w. CUNNIFF I 2,374,666

ELECTRONIC DEVICE CIRCUIT AND METHOD Filed March 11, 1941 2 Sheets-Sheet l SINUSOIDAL llc- YOLTJEE SUPPLY 0 A T /Z A INVENTOR '5 J I 17 7710MA5 M. Cu/v/v/FF ATTORNEYS Patented W ley l, tees merino DEVICE.

, Newark, N. 3., asslgnor to -Sol Lamp Works line, Newark, N. 3., a

corporation of Delaware Application March 11, ran, serial No. states (oi. ire-5.8)

l2 Cla.

This, invention relates to electronic devices, circuits and methods.

One object of the invention is a novel electronic generator or converter and circuit for producing pulsating electrical voltages or waves of a predetermined character, and a particular object is a generator for producing a saw-tooth voltage which by reason of its special character is particularly useful in the electronic art.

A further object or" the invention is a novel and improved circuit for utilizing the electronic enerator and circuit above referred to.

A further object of the invention is a novel method of producing a special voltage wave. A further object of the invention is the utilization of an electron beam and resistance circuit for converting an alternating wave into a special wave shape.

A further object is the utilization of an electron heam as a commutator for producing a sawtooth voltage.

The principle of the generator of this invention is of general application, but a particular object is to produce a pulsating voltage of the saw-tooth variety which is better adapted to the vertical or horizontal deflection of the electron beam in a television picture pick-up tube or a television picture reproducing tube than the pulsating voltages produced by prior devices and circuits. As applied to television the invention has among others the following advantages: The number of elec= tronic tubes required in the conventional system may be substantially reduced, as for example, two tubes may be utilized to replace as many as six tubes of the conventional system; more of the time used in transmitting may be devoted to actual picture transmission; the entire synchronizing is or may be etiected on the sound reception side of the circuit; the full magnitude of the wave is now available for the purpose of sending the picture signal the picture is less subject to the efi'ect'ci electrical interference: and the new system permits greater flexibility in the use of frame and line frequencies.

Other objects of the invention will hereinafter appear.

For a better understanding oi the invention. reference may be had to the accompanying drawings forming a part oi this application-wherein- Fig. l is a perspective view diagrammatically illustrating the principle of the generator and cir- Figs. 4 and 5 are plan and sectional views of a target which may be used with my invention;

Figs. 6 and 7 are perspective and sectional views of a modified form of target for use with the invention;

Fig. 8 is a view illustrating one of the wave forms produced by the generator of this invention;

Fig. 9 is'a diagrammatic viewot a television system embodying the invention; and i Fig. 10 shows a modified target.

Referring to Fig. 1 of the drawings, the generator, which may .be termed an electronic wave converter. is illustrated as embodying an enclosure 5 which can be ofuglass for the purpose of permitting the tube to be evacuated or filled with gas. The generator or converter, aside from the circuits, embodies essentially three elements, namely an electron gun A, a beam deflectin means B and a target C. The electron gun A is for the purpose of producing and projecting the electron beam in the direction of the target C and may be of any conventional character with conventional circuits. The target 0, in the particular embodiment illustrated, is a resistance in the shape of a slotted or interrupted annulus, the

, gap in the resistance being indicated at it. This resistance element may have a varying resistivity or, as is preferred for television, should have a constant or uniform resistivity throughout. The beam deflecting means B in the embodimentshown comprises two pairs of deflecting plates 6 and 5 which are mounted at right angles to each other above the electron gun A or between the gun and the target C. This deflecting means is mounted so as to permit the deflection of the electron beam to any position on the target, and

nected to one pair of the plates 3 and 5 while the other pair, of plates ii and E is connected with a conductor leadingto and connected at a point between a resistance H and a capacity 82 connected across the single phase line 8, t.

A circuit D is connected with the terminals of the slotted or interrupted annular resistance element G and a circuit E is connected between one of the lines of the circuitD and the cathode it of the electron gun A. To one of these circuits D and E is applied a constant D. C. voltage and from the other is obtained the output voltage of the wave-shape desired, as for example, a sawtooth wave-shape particularly suitable for television. In the preferred arrangement (Fig. 3) the constant direct current voltage is applied to the circuit E. When the direct current source is connected with the circuit D, a resistance is preferably connected across the circuit E.

Upon the application of a sinusoidal A. C. voltage across the terminals 8 and 9 and or a constant direct current voltage across the terminals E, the electron beam produced by the gun A is deflected onto the target and caused to traverse and follow the same at a uniform rate depending on the frequency of the A. C. supply voltage. This beam acts as a moving commutator, producing a, sawtooth output voltage across'the terminals D. The frequency of the output voltage is equal to the frequency or the A. C. voltage across the terminals 8 and while the magnitude of the output voltage depends on the resistance of the element C and on the beam current. As indicated, the output voltage wave-shape may be varied by providlng a target C of a non-uniform resistivity.

When the direct current voltage is applied to the circuit D, the output saw-tooth voltage, as above indicated, is produced on the circuit E, and in this case the magnitude of the output voltage depends on the voltage across the terminals Ti and i, and the wave-she es-may be varied'by providing a target of non-uniform resistivity or by applying other than D. C. voltage across the circuit or by altering the shape oi the target.

In the embodiment 'of Fig. 2 the deflecting means B instead of being within the envelope 5 is disposed exteriorly oi the tube and in this case this deflecting means preferably comprises two pairs of coils 3, d, being shown in the drawing displaced 90 from each other, and the pairs of coils l, 5 are supplied with alternating current difiering in phase as for example by 90, the supply circuit being omitted for convenience in illustration. In this case the electron beam is elec tromagnetically deflected while in the embodiment of Fig. l the beam is electrostatlcally de= fiected.

The target C is preferably formed of a thin annular layer or coating of resistance material which is slotted or interrupted at ill, and in the particular embodiment shown this is formed of carbon carried by a mica disc ll. This carbon resistance may be spraying on to the mica disc l'l while the carbon is in the colloidal form, and the commercial colloidal carbon sold under the tradename Aquadag has given satisfactory results. The ends or terminals of this resistance target C are connected with the terminals and 2! leading to the circuit D, and this connection may be made in any suitable manner. It is understood that the resistance coating or target C is carried on the side of the mica or other insulating disc 57 exposed to the electron beam.

In the embodiment of Figs. 4 and 5 the target C extends all the way around the disc I! except for the interruption or gap at 16, the disc itself being solid and uninterrupted. In the embodiment of Figs. 6 and 7 the disc W is itself slitted at 56, preferably along a radius, and the two adjacent edges at the slit are slightly displaced laterally of the plane oi the disc so as to form a gap in the target resistance C, the ends of the latter extending to and through the slit it to the opposite side of the disc. In this case the terminals asvaecc 2b and ii are formed of sheet metal tabs which are fastened to the disc I! in any suitable manner as for example by means oi the screws or rivets 22, and the terminal 20 is formed with a projection 23 turned at right angles thereto into engagement with the disc at a point on the other side of the slit it for the purpose of maintaining a gap it between the ends of the annular resistance C. The carbon resistance C is extended around the edges of the walls of the slit l6 and extends under the terminals 29 and 2| to form the electrical connection. The terminals 24 lead to the circuit D.

As above indicated the electron gun A and the circuit for producing the electron beam may be of any conventional character. In the particular embodiment of Fig. 3 a direct current source 25 is connected to a resistance 26 and the latter has taps leading respectively to the conductor lb and the first anode t'l. The conductor it is also connected with the second anode 528. The control grid 29 is connected through a conductor with one side of a battery 3i while the other side of this battery is connected with the line Fig. 8 illustrates the shape of the voltage wave obtained from the-circuit D. dotted wave indicates approximately the shape of the wave obtained by conventional devices and circuits, while the full-line wave indicates the wave obtainable according to the invention 01 this application. It is observed that there is considerable time wasted in the conventional wave in the drop from the maximum to the minimum, whereas in the wave produced according to the present invention the drop is substantially vertical, with the advantages indicated above. The points K,

Y and Z of the wave correspond to the points X.

Y and Z on the resistance element C successively traversed by the electron beam 3.

In the circuit D are illustrated condensers of suitable capacity.

Fig. 9 illustrates diagrammatically a television system embodying the invention. First is a radio receiver which may be of conventional design for the purpose of receiving radio signal, which consists both of the sound accompanying the television signal and the synchronizing signals, this being indicated at 36. in the output circuit of the radio receiver are two filters 3?, one of which separates the vertical deflection synchronizing signal, while the other separates the horizontal deflection synchronizing signal. The sinusoidal output voltages from these filters are applied to the electronic wave converters which convert the sinusoidal synchronizing signals into saw-tooth voltage waves, the latter being used for the purpose of horizontal and vertical deflection of the electron beam in the picture tube 40. Another radio receiver circuit II which receives the picture portlonof the television signal is connected to the control grid 42 of the picture tube 40. It is understood that the picture tube may be 01 any conventional type having any conventional deflecting means 43 and conventional electron gun 44.

This converter is of general application and has a number of important uses. As applied to television it has the following advantages: Two tubes replace six tubes of the conventional system. More of the time used in transmitting may be devoted to actual picture transmission. Previously a rather large part of the time was de' voted to the transmission of synchronizing pulses. The time necessary for transmitting those pulses may be either reduced or eliminated, possibly.

insulating disc being slit at one point throughout the width of the annular coating with the edges of the slit being displaced laterally of the plane 01' the disc to form a gap in the resistanceelement while at the same time presenting a substantially continuous annular resistance target in directions normal to the plane of the disc 7. In an electronic wave converter, an en- I velope conta ning therein an electron gun and an annular resistance element disposed generally in a plane at right angles to the axis of the electron gun and adapted to receive the electron beam generated by the electron gun, means for deflecting said beam and causing it to traverse said annular resistance element, said annular resistsnce element being interrupted at one point to form a gap therein, a direct current voltage circuit and an output circuit, one of said circuits being connected to the terminals of said resistance element and the other of said circuits being connected between the electron gun and one of said terminals, the deflecting means comprising two pairs of plates disposed between the elec= tron gun and the annular resistance element, with said plates being energized in pairs from sinusoidal alternating current supply circuits differing in phase by 90.

8. Means for producing a source of electric current having a predetermined wave shape comprising means for generating an electron beam, a resistance element of circular shape having a gap formed therein and disposed generally in a plane at right angles to the beam, means causing said beam to traverse said ele ment at a predetermined rate as a commutating element, and an electrical circuit connected to said element at opposite sides of said gap.

9. In a television system, the combination including means for receiving radio signals and converting said signals into sinusoidal alternating waves, a picture tube having vertical and horizontal deflection means, and a pair of electronic wave converters each comprising the means set forth in claim 1, and each connected between said first mentioned means and one oi said deflection means for converting the sinu-' soidal waves into saw-tooth voltage waves for application to said deflection means.

10. In an electronic wave converter, an envelope containing therein an electronic gun and an annular resistance element disposed generally in a plane at right angles to the axis of the electron gun and adapted to receive the electron beam generated by the electron gun, means fordeflecting said beam and causing. it to traverse said annular resistance element, a direct current voltage circuit and an output circuit, one of said circuits being connected to said resistance element to cause a current to flow therethrough and the other of said circuits being connected between the electron gun and said resistance element.

11. In an electronic wave converter, an envelope containing therein an electronic gun and an annular resistance element disposed generally in a plane at right angles to'the axis of the electron gun and adapted to receive the electron beam generated by the electron gun, means for deflecting said beam and causing it to traverse said annular resistance element, a direct current voltage circuit and an output circuit, one of said circuits being connected to said resistance element to cause a current to flow therethrough and the other of said circuits being connected between the electron gun and said resistance element, said annular resistance element is continuous with the circuits connected at different points thereof.

12. Means for producing a source 0! electric current having a wave approaching a saw-tooth Wave shape comprising means for generating an electron beam, an annular resistance element which is interrupted at one point, and disposed generally in a, plane at right angles to the beam means causing said beam to traverse said element and the interruption therein at a predetermined rate as a conmiutating element, and a circuit connected to said element at either side of the interruption.

' THOMAS W. CUNNIFF.

CERTIFICATE CF CORRECTION.

Patent use Zach-96660- my 1, 19 1s.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 511., for "spraying" read --sprayed--; page L second column, line 52, claim 11, for "cijleziuant is read "element be1ng--;-and thatthe said Letters Patent should horned with this correctlon therei n that the same may conform to the record or the case in the Patent Office.

Signed andsealed this 51st day of July, A}. D. '19l 5.

. (Seal) Leslie Frazer Acting Canmissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2,57%666. May 1, 1915.

moms w, CUNNIFF.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column line 5b., for "spraying" read "sprayed"; page 1;, second column, line 52, claim 11, for "element is" read -element being"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed andsealed this 51st day of July, A. D. 19b

Leslie Frazer (Seal) Acting Commissioner of Patents. 

